Plastometer



March 13, 1956 L. s. BLUMENBAUM PLASTOMETER 2 Sheets-Sheet 1 Filed July 24, 1955 m i a A w B 6 m 2 -l .9 3w 6 e o /o 2 7 8 2 M 2 United States Patent'O PLASTOIVIETER Louis G. Blumenbaum, Cranston, R. I., assignor to Scott Testers, Inc., a corporation of Rhode Island Application July 24, 1953, SerialNo. 370,150

3 Claims. 01. 73-101 The invention relates to improvements in a plastometer,

particularly the plastometer disclosed in Patent No. 2,037,529, issued April 14, 1936, to Melvin Mooney. In the apparatus disclosed in the above patent two separate manually operable levers are employed to pro vide the necessary length of movement and leverage for moving the upper die into engagement with the lower die and severing the excess of the sample material about the die parts so as to provide for a proper closing of said dies. 7 p

The general object of the invention is to provide, in an apparatus of the above type, means for providing the necessary distance of travel and leverage operable by a single lever for lowering the upper die into engagement with the lower die and severing the excess of the sample material about the die parts.

A more specific object of the invention is to provide means arranged for providing and combining an eccentric movement with a linear movement so as to provide the necessary distance of travel and leverage operable by a single lever for lowering the upper die into engagement with the lower die and severing the excess of the sample material about the die parts. I

' Another object of the invention is to provide for lowering the upper 'die by a rack and pinion arrangem ent operable by a single lever.

Another object of the invention is to provide for slidably guiding the lowering of the upper die in a manner to prevent binding between the slidahle part and to assure accurate register with the lower die.

With these and other objects in view, the invention. consists of certain novel features of construction as will be more fully described and particularly pointed out in the appended claims. In the accompanying drawings:

Figure l is an elevational view partially in section of a plastometer embodying my invention; I

Figure 2 is a sectional view taken substantially along line 2-2 of Figure l;

Figure 3 is a similar view of a fragmental portion of that shown in Figure'Z with certain elements shown'in different relations to each other; and

Figure 4 is a view of a fragmental portion ofthe apparatus shown in Figure 1 looking in the directionof the arrows on line 4-4 of Figure 1.

The plastometer or machine for measuring the {viscosity and elastic recovery of rubber and plastic materials generally, according to the invention has a single manually operable lever which is rotatable with a shaft which 'plastometer or machine of the type shown in the above 2,737,805 Patented Mar. 13, 1956 P ICC on which the upper die is mounted. The other end of the link is connected to the first said lever at a location thereon eccentric to the axis of the shaft. In moving the manually operable lever through 180 degrees, the platen Will be moved the distance one half of the said circumference of the gear plus that provided by the crank-like mounting of the said link, which combined distance is provided with a comparatively small crank arm and ample to provide sufiicient separation between die parts for convenience of loading and unloading thereof. There will also be an increase in the leverage or force applied to close the die parts, since the fulcrum or turning point of the lever will be inwardly the distance of the radius of the spur gear.

Referring to the drawings, 8 designates generally a patent to which reference is made for a more detailed showing and description thereof. The machine comprises a base 9 having a plate 10 from the under side of which depends a bearing 11 in which there is journalled a vertical shaft 12. A worm wheel 13 (see Figure 2) is secured to the lower end of the shaft and is engaged by a wormvl4 on a horizontal shaft 15 which is journalled. inbearings 16 and 17. A spur gear 18 is is free to move in a linear vertical guided path. A spur gear is mounted on the shaft to rotate therewith and engages a tooth track or gear rack which is held stationary in a vertical direction. Thus, as the lever is swung, as I for example 180 degrees, the gear, shaft and lever. are moved in a vertical direction a distance substantially equal to one-half the circumference of the spur gear taken on the pitch line of the gear. A connecting lever or link is attached at its lower end to the upper platen mounted on the shaft 15 and is engaged and rotated by a similar size but wider spur gear 19 on shaft 20 which may be driven or rotated from any suitable power source, such as an electric motor (not shown). The shaft 15 is additionally mounted for axial movement and the right end portion thereof, as seen in Figure l, is journalled in a ball bearing (not shown) housed in a bearing block 21, the lower end of which has a foot portion 22 (see Figure 4) which slidably engages spaced rollers 23 which are supported on brackets 24. Thus, the bearing block is' held against rotational movement with the shaft but is movable axially therewith.

A knife edge 25 (see Figure 1) extends outwardly from the bearing block 21 and moves therewith and is engaged by one arm 26 of a U-spring, the other arm 27 of which is held in fixed position between a clamp plate 28 and a bracket 29 to which the plate 28 is secured as by means of cap screws 30. Thus, the shaft 15 is resiliently biased or spring loaded against axial movement towards the right. A dial gauge 31 having a stem 32 is attached to the opposite side of the base, and the stem 32 extends into engagement with the adjacent end of the shaft 15 whereby any axial movement of the shaft 15 will be indicated on the gauge.

' On the upper side of the plate 10 there is mounted the lower platen 33 which has a circular central recess 34, the bottom wall of which has a central bore 35. The lower die 36 is received in the recess 34 and has a reduced boss 37 through which a central bore 38 extends in register with the bore 35. The die is held in place by a die holder 39 which is secured to the platen by cap screws '40 which pass through the holder and die to extend into threaded engagement with the platen. The holder 39 has a central bore 41 in which projects the reduced boss 37 which provides with the walls of the said bore 41 a cavity 42, the upper edge of which is provided with a knife edge 43. A rotor 44 is received in the cavity 39 and has a stem 45 which extends through the bores 35, 38 and into engagement with the shaft 12 to rotate therewith.

The upper die 36' is substantially similar to the lower die 36 with the exception that there is no central bore therethrough and like elements thereof are indicated with a similar but primed numeral. The die 36' is attached in a similar manner to the upper platen 33 which is attached to a plate 46 as at 47 (see Figure 2). A bracket 48 having spaced apertured lugs 49 (Fig. l) is attached to the upper side of the plate 46 by cap screws 50. The

lower" end of 'a'yck'e lever 51 is received between the lugs" 49 and is pivotally "secured thereto '"by' a pivot pin 53. The lever extends from the plate in a general vertical direction and has a forked end with arms 52 to be connected to a'manually operablelever54"iri a'ma'iiner which'will hereinafter be described. v l

The lever 54 has 'an'operating handle 5at the end ofwhich'there is formed a bifurcated i'portion56 providing spaced arms 57 which are joined to each'other by a bridge '58 from which the handle55 extends. The arms 57 are mounted on a shaft59'which is journalled in roller bearings 69. A spur'gear 61 is mounted on the shaft 59 at a position between'the said'arm's 57 and a key 62 or other fastening secures the lever andgeanto the shaft to rotate therewith. Theball bearings are slidably mou'ntedin guide slots 63 formed in an'upper supporting structure designated 'generally'64 having vertical sides 65 joined by a horizontally extending bridge 66 and attached as by'screws 67 'to ahorizontal plate 68 supported above the base '9 by 'twopairs of vertical columns or posts 69, 76 which'rise from theplate 10 and a're'secured thereto as at 71 and at their upper end to theplate 68 as at 72. p

The arms 52 of the yoke lever'51 straddle the arms 7 and are pivotally attached thereto as at 73 to be eccentric to the axis of rotation of the said arms 57. A toothed rack 74 which is engaged by thefspur gear 61 is fastened to the bridge 66 by cap screws 75 and thereby held stationary and provides a track "alongwhich 'the spur gear may be rotatably moved.

Inthe raisedposition of the upper platen 33' asshown in full lines in Figures 1 and 2, the lever 54 extends generaily'horizontal as shown. In swinging the lever in a counter-clockwise direction, as seen in Figure 2, the spur gear 61 will be rotated in the same direction and willbe'moved downwardly by its engagement with the rack '74. The yoke lever 51 will likewise 'be'movedin'a downwardly direction through its eccentric connection to the'lever 5d and move the upper platen 33 towards "the lower platen 33 to place the upper and lower'dies into engagement with each other as shown in Figure 3, 'at which position the yoke lever 51 will be substantially in vertical position as shown in this Figure 3. With a view of predetermining the lower limit of travel of the upper die 36', the lever 54 is provided with an abutment 76 which at the lower limit of the swing of the lever willengage an adjustable stop 77 which 'is adjustably secured on a lateral brace 77' connecting the lower end portions of the sides 65.

Thedie 36 is guided in its movement towards and into engagement with the lower die 36. To' thisend guide bearings 73 having semi-circularbearingsurfaces 79 (see Figure l) and a foot portion '80 are mounted onthe plate 46 and securedthere'to by c'ap'screws81. The pair'of columns 69 arepositioned'on oppositesides of'the platen 33 and in line with each other. Th'e'se columns 69 provide guides engagedby'the'surfaces 79 to guide the. platen 33. With a'viewofeliminating any binding action between the guide columns'69 and the bearings 78, the columns69 are slightly'tapered as' at 83. The'lower end portion of each column'69 for a distance at least equal to'the width of "the lower" bearing surface 79 of the guide hearing 78 is straight. 'Thus as the upper die 36 is lowered, the guide bearing 78 will be reasonably free of frictional contactwith the' guide column when moving along the tapered po'rtion 83. Upon'the bearings 78 passnig into the portions82, the

"the lower die 36.

As previously indicated, the machine is for measuring the viscosity and the elastic recovery of rubber and plastic materials generally. The sample to be measured is placed across the lower die 36 and the upper die 36 is lowered to force the sample to fill the cavity of the closed dies, the surplus material being severed by the knife edges 43 of the dies. It is here pointed out but not shown that the dies are heated by units enclosed within the platens. The power sourcemaynow'be applied to rotate the rotor 44, which will exert a shearing action on the sample held against movement in the cavity formed by the closed dies. The resistance of the specimen to deformation by the shearing action of the rotor develops a thrust in the shaft 15 tending to axially move the same against the opposing resilient bias on the shaft 15. The axial movement of the shaft is ;followed by'the stem 32 of the gauge 31. Thus, the-distance of axial movement of the shaft'by the said thrust against the known bias or loading of the rnachineis indicated on the gauge.

I claim:

1. In a measuring machine comprising means for'subjecting a constant volume ofplastic material to' a shearing action between two dies, said dies comprising a stationary die and a second die movably mounted for-movement to and from the stationary die, a manually operable lever operable for moving said seconddie into engagement with the said stationary die, said lever being mounted for rotational and linear movement, and a link for connectingsaid'lever to said movable die, said link being mounted On 'said leverat a location eccentric to the axis of rotation of said lever.

2. In a measuring machine comprising means for subjecting a'constant volume of plastic material to a shearing action'between two dies, said dies comprising a stationary die and a second die movably mounted for movement to and from the stationary die, a manually operable lever'operable for moving said second die into engagement with the said stationary die, said lever being mountedfor'rot'ational and linear movement, a guide engaged with said lever for guiding said lever to move in a vertical path, and a link operatively connected'at one-end to said movable die and at the other end thereof to said lever at a lo'cation'ther'eon eccentric to the axis of rotation of the said lever. v

3. In a measuring machine comprising means for subjecting a constant volume of plastic material to a shearing action'bet'ween two dies, said dies comprising a stationary die and'a' second die movably mounted for movement to and from the stationarydie, a rotatable shaft, 'means for guiding said shaft for movement in a linearpath, a

- lever fixed 'to said shaft for rotating the same, a' spur gear fixed to said shaft, a toothed track engaged by said gear' for advancing said gear along said track, and a link eccentrically mounted on said lever and extending into engagement with said movable die tomove thesame upon swingingof said'lever.

' References Cited in the tile of thispate'nt UNITED STATES PATENTS 1,197,824 --H6SS Sept. 12, 1916 1,817,210 Salsbury -Aug." 4, 1931 1,934,392 Warden NOV. 7, 1933 2,037,529 Mooney 'Apr. '14, 1-936 

1. IN A MEASURING MACHINE COMPRISIING MEANS FOR SUBJECTING A CONSTANT VOLUME OF PLASTIC MATERIAL TO A SHEARING ACTION BETWEEN TWO DIES, SAID DIES COMPRISING A STATIONARY DIE AND A SECOND DIE MOVABLY MOUNTED FOR MOVEMENT TO AND FROM THE STATIONARY DIE, A MANUALLY OPERABLE LEVER OPERABLE FOR MOVING SAID SECOND DIE INTO ENGAGE- 